A U.S. lawmaker on Thursday pressed the U.S. Defense Department for further details on what information the U.S. military shared with Chinese engineers as part of a cloud computing services contract with Microsoft.

Microsoft says it will no longer use China-based engineers to support the Pentagon. But ProPublica found that the tech giant has relied on its global workforce for years to support other federal clients,

Chinese hackers gained access to the U.S. government agency that oversees nuclear weapons in a widespread Microsoft hack. Microsoft issued an alert Tuesday warning that hackers affiliated with the Chinese government have been exploiting cybersecurity vulnerabilities in the company’s SharePoint software.

National security experts expressed alarm over Microsoft's practices allowing China-based engineers access to Pentagon cloud systems after a ProPublica investigation.

A series of cyberattacks targeting Microsoft collaboration software, specifically SharePoint, have been linked to Chinese hackers and threat actors.

Following criticism of the company’s use of Chinese workers to advise on operation of Department of Defense cloud systems, Microsoft has changed its policy.

Chinese hackers breached the U.S. National Nuclear Security Administration through Microsoft SharePoint, with the Energy Department confirming no sensitive information was stolen.